Imaging 5-HT1A receptors with positron emission tomography: initial human studies with [11C]CPC-222.
The novel radioligand [11C]CPC-222 (N-[2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl]-N-(2-pyridinyl)-2-bicyclo [2,2,2]octane carboxamide) was evaluated as an in vivo probe of the 5-HT1A receptors using positron emission tomography (PET). Three human volunteers were imaged with PET over a 90 min period following intravenous injection of the radioligand. There was a high accumulation of the radioligand in brain regions with a high density of 5-HT1A receptors. The peak cortical concentration was 1.0-2.5% of the injected dose per litre. The ratio of radioactivity in receptor-rich regions to that of the cerebellum reached a plateau of 2.5-4.0 by 45 min after injection. Analysis of the plasma revealed no detectable amount of the potential metabolite, radiolabelled WAY-100634. This new radioligand has suitable properties to study the 5-HT1A receptors in man with PET.
Houle
S
S
V.M. Rakoff PET Centre, Clarke Institute of Psychiatry, Toronto, Ontario, Canada.
Wilson
A A
AA
Inaba
T
T
Fisher
N
N
DaSilva
J N
JN
D000328:Adult; D001921:Brain / Q000000981:diagnostic imaging / Q000378:metabolism*; D002250:Carbon Radioisotopes / Q000493:pharmacokinetics; D002531:Cerebellum / Q000000981:diagnostic imaging / Q000378:metabolism; D002540:Cerebral Cortex / Q000000981:diagnostic imaging / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D008297:Male; D010880:Piperidines / Q000493:pharmacokinetics; D011725:Pyridines / Q000493:pharmacokinetics; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D011985:Receptors, Serotonin / Q000032:analysis*; D044263:Receptors, Serotonin, 5-HT1; D012016:Reference Values; D013997:Time Factors; D014018:Tissue Distribution; D014055:Tomography, Emission-Computed / Q000379:methods
C111190:CPC 222; D002250:Carbon Radioisotopes; D010880:Piperidines; D011725:Pyridines; D019275:Radiopharmaceuticals; D011985:Receptors, Serotonin; D044263:Receptors, Serotonin, 5-HT1